1. Field of the Invention
The present invention relates to a sprinkler system. More particularly, the present invention relates to a wet-pipe sprinkler system, a method of supplying water and dealing with water leak in the sprinkler system.
2. Description of the Related Art
A sprinkler system is an automatic fire-fighting system installed in the ceiling of a building or a structure. The system includes a sprinkler head that operates according to ambient thermal conditions, a series of interconnected pipes through which water is supplied to the sprinkler head, and at least one water supply. In general, there are two types of sprinkler systems: a wet-pipe sprinkler system and a dry-pipe sprinkler system. In a wet-pipe sprinkler system, a sprinkler head is filled with water. In a dry-pipe sprinkler system, the pipes are filled with air. The present invention relates to a wet-pipe sprinkler system.
A wet-pipe sprinkler system typically includes a main pipe through which water is supplied to a sprinkler head from a water supply and an auxiliary pipe on which the sprinkler head is installed. A main valve, which controls the overall inflow of the water from the water supply to the sprinkler system, is installed in the main pipe. The sprinkler head includes a heat fusible cap that tightly shuts an orifice during normal situations (i.e., no fire present), but automatically breaks to pieces and detaches from the sprinkler head during a fire. In the wet-pipe sprinkler system, both the auxiliary pipe and the main pipe are filled with water under a predetermined pressure, e.g., at a pressure of 6 kgf/cm2. Therefore, in order to extinguish a fire, water can be rapidly discharged from the orifice when the heat fusible cap comes off the sprinkler head and the sprinkler head operates.
However, there are some problems associated with a conventional wet-pipe sprinkler system. First, a conventional wet-pipe sprinkler system is vulnerable to a physical phenomenon referred to as “water hammering” during the filling of a pipe with water. Water hammering is due to a rapid change in pressure of the water contained in a pipe caused by a sudden change in kinetic energy. The rapid change in pressure directly affects a pipe, thus generating a vibration and impulse noise therein. In a worst-case scenario, flooding of neighboring areas is caused by damage to a pipe. Therefore, it is important to prevent water hammering from occurring during the filling of a pipe with water. Water hammering frequently occurs when the main valve is opened to fill a pipe with water because the pressurized water from the water supply suddenly enters the pipe. For this reason, in the past, the sprinkler system was filled with water only by a water-filling pipe connected to the main pipe with the main valve closed, and the main valve was opened after the filling. In the above method, a pipe having a smaller diameter than the main pipe is used as a water-filling pipe so that water does not flow into the pipe too rapidly, thereby preventing water hammering. However, since the opening and shutting of the main valve is manipulated by a person, e.g., a system manager, water hammering may occur in a case where the main valve is mistakenly opened by the system manager before the sprinkler system is completely filled.
Additionally, it is inconvenient to monitor a leak in the pipes or sprinkler head and to stop the leak in a conventional wet-pipe sprinkler system. For instance, when the system operates due to malfunction or breakage of the system, water pressurized in the sprinkler head or pipes floods neighboring areas. Damage may be enormous when such an accident occurs in a clean room where semiconductor devices are manufactured, due to, for example, immersion of expensive tools for manufacturing semiconductor devices. In such a case, the water supply must be blocked by shutting the main valve immediately and rapidly draining water from a pipe to the location of the fire. However, in the conventional wet-pipe sprinkler system, valves are manually opened and closed by a person, such as a system manager, and thus the process of blocking water supply and draining water cannot be done immediately. Therefore, it is not possible to take quick measures when a pipe or a sprinkler head is leaking, thereby resulting in water damage.